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I love my coffee [Bitter Coffee, Better Health?]

I love my coffee. Who doesn’t want (or need for all you coffee addicts out there) a cup of freshly brewed java to start their day? However, the bitterness of coffee is something most of us could do without.
Now chemists in Germany and the U.S. say they have identified the chemicals that are largely responsible for coffee’s bitterness. Their study, one of the most detailed chemical analyses of coffee bitterness to date, was presented this week at the 234th national meeting of the American Chemical Society.

Contrary to popular belief, only 15% of coffee’s perceived bitterness is due to caffeine. In fact, coffee is a complex mixture of chemicals and an estimated 25 to 30 compounds have been thought to contribute to coffee’s bitter taste. Surprisingly, however, the chemists found that coffee’s bitterness is due to two main classes of compounds produced during the roasting process; chlorogenic acid lactones and phenylindanes. Both compounds are antioxidants and are not present in green, unroasted coffee beans.

During roasting, chlorogenic acid, a polyphenol in raw beans, is converted to chlorogenic acid lactones. Further roasting results in the breakdown of the lactones to phenylindanes. The lactones are responsible for the mild bitterness of light- to medium-roasted coffee, while the second breakdown product, phenylindanes, produce the harsh, bitter taste of dark-roasted coffee.

Chlorogenic acid lactones have been known for some time to be produced by the roasting process, but their role as a source of bitterness was not known until now. Perhaps more importantly, the identification of phenylindanes adds to the growing body of knowledge investigating the health benefits of coffee.

What You Say??? Health Benefits????
Indeed, coffee consumption offers a number of potential health benefits. The results of epidemiological research suggest that moderate coffee consumption may help prevent type 2 diabetes mellitus, Parkinson’s disease and liver disease. Although coffee consumption has not been found to be associated with significantly increased cardiovascular disease risk, it is associated with increases in several cardiovascular disease risk factors, namely blood pressure and plasma homocysteine. Some individuals may be more vulnerable to the adverse effects of caffeine in coffee, including people with hypertension, children, adolescents and the elderly. Nevertheless, habitual intake of caffeinated beverages may prevent heart disease in the elderly.

It’s been suggested that this research on coffee bitterness will lead to a “better cup of joe”. However, I wouldn’t be too surprised if the the compounds that give coffee its bitter taste also turn out to be responsible for coffee’s health benefits.

References
  1. Battling Bitter Coffee: Chemists Identify Roasting As The Main Culprit. ScienceDaily 2007 Aug 22.
  2. Farah et al. Effect of roasting on the formation of chlorogenic acid lactones in coffee. J Agric Food Chem. 2005 Mar 9;53(5):1505-13. 
  3. View abstract Salazar-Martinez et al. Coffee consumption and risk for type 2 diabetes mellitus. Ann Intern Med. 2004 Jan 6;140(1):1-8.
  4. View abstract van Dam and Hu. Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA. 2005 Jul 6;294(1):97-104.
  5. View abstract Ascherio et al. Prospective study of caffeine consumption and risk of Parkinson’s disease in men and women. Ann Neurol. 2001 Jul;50(1):56-63.
  6. View abstract Ruhl and Everhart. Coffee and tea consumption are associated with a lower incidence of chronic liver disease in the United States. Gastroenterology. 2005 Dec;129(6):1928-36.
  7. View abstract Noordzij et al. Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. J Hypertens. 2005 May;23(5):921-8.
  8. View abstract Olthof et al. Consumption of high doses of chlorogenic acid, present in coffee, or of black tea increases plasma total homocysteine concentrations in humans. Am J Clin Nutr. 2001 Mar;73(3):532-8.
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Saya suka kopi saya. Siapa yang tidak ingin (atau membutuhkan semua pecandu kopi di luar sana) secangkir jawa yang baru diseduh untuk memulai hari mereka? Namun, kepahitan kopi adalah sesuatu yang kebanyakan dari kita dapat lakukan tanpa.

Sekarang para ahli kimia di Jerman dan AS mengatakan mereka telah mengidentifikasi bahan kimia yang sebagian besar bertanggung jawab atas kegetiran kopi. Studi mereka, salah satu analisis kimia paling rinci dari kepahitan kopi hingga saat ini, disajikan minggu ini pada pertemuan nasional 234 American Chemical Society.

Bertentangan dengan kepercayaan populer, hanya 15% dari rasa pahit yang dirasakan kopi adalah karena kafein. Bahkan, kopi adalah campuran bahan kimia kompleks dan diperkirakan 25 hingga 30 senyawa telah diduga berkontribusi terhadap rasa pahit kopi. Anehnya, bagaimanapun, para ahli kimia menemukan bahwa kegetiran kopi adalah karena dua kelas utama senyawa yang dihasilkan selama proses roasting; asam klorogenat lakton dan fenilindan. Kedua senyawa tersebut adalah antioksidan dan tidak ada dalam biji kopi hijau, yang tidak digiling.

Selama memanggang, asam klorogenat, polifenol dalam biji mentah, diubah menjadi asam klorogenat lakton. Hasil pemanggangan lebih lanjut dalam pemecahan lakton menjadi fenilindan. Lakton bertanggung jawab atas kepahitan ringan kopi yang dipanggang sampai sedang, sementara produk pemecahan kedua, fenilindan, menghasilkan rasa pahit yang keras dan gelap dari kopi panggang.

Asam klorogenik lakton telah dikenal selama beberapa waktu untuk diproduksi oleh proses roasting, tetapi peran mereka sebagai sumber kepahitan tidak diketahui sampai sekarang. Mungkin yang lebih penting lagi, identifikasi fenilindan menambah pengetahuan yang berkembang untuk menyelidiki manfaat kesehatan kopi.

Apa Kamu Ucapkan??? Keuntangan Buat Kesehatan???
Memang, konsumsi kopi menawarkan sejumlah manfaat kesehatan potensial. Hasil penelitian epidemiologi menunjukkan bahwa konsumsi kopi sedang dapat membantu mencegah diabetes mellitus tipe 2, penyakit Parkinson dan penyakit hati. Meskipun konsumsi kopi belum ditemukan terkait dengan peningkatan risiko penyakit kardiovaskular secara signifikan, hal ini dikaitkan dengan peningkatan beberapa faktor risiko penyakit kardiovaskular, yaitu tekanan darah dan homosistein plasma. Beberapa individu mungkin lebih rentan terhadap efek buruk kafein dalam kopi, termasuk penderita hipertensi, anak-anak, remaja dan orang tua. Namun demikian, kebiasaan minum minuman berkafein dapat mencegah penyakit jantung pada orang tua.

Telah disarankan bahwa penelitian tentang pahit kopi ini akan mengarah pada "cangkir joe yang lebih baik". Namun, saya tidak akan terlalu terkejut jika senyawa yang memberikan rasa pahit kopi juga ternyata bertanggung jawab atas manfaat kesehatan kopi.
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